ABSTRACT
The biochemical initiation of puberty follows many years of quiescent hypothalamic-pituitary-ovarian function. Pubertal progression may be altered by genetic variations, congenital or acquired structural defects of the brain, congenital or acquired defects of the ovary or its life span, nutrition, stress, or chronic disease. Timing of puberty refers specifically to when pubertal events occur, and certain pubertal events mark this timing, namely, thelarche and menarche. Pubertal progression can be an early indicator of underlying health conditions in a child. Evaluating both the timing and the tempo of puberty permits the practitioner to identify both normal, familial variations in puberty as well as pubertal disorders of precocity or delay. Precocious puberty describes pubertal changes occurring more than 2.5 standard deviations earlier than the mean. Central precocity is characterized by growth acceleration, bone age advancement, thelarche, and adrenarche occurring at earlier than expected ages, with pubertal levels of luteinizing hormone and follicle-stimulating hormone.
